Sanctification Lesson 1 Part I Study Notes

The lesson in one minute

Sanctification means being made holy by God's grace. The Holy Spirit applies Christ's death and resurrection to believers, renewing the whole person. This involves an ongoing dying to sin and rising to new life. The goal is deeper devotion to God and life in his presence, not simply avoiding wrongdoing. The professor's two guiding questions are “What is sanctification for?” and “How does it proceed?” (Westminster Larger Catechism (WLC) Q. 75; Westminster Shorter Catechism (WSC) Q. 35; Westminster Confession of Faith (WCF), ch. 13.)

What sanctification is

WLC Q. 75 supplies starting definition. Break it into parts:

1. Source: It is God's grace, carried out by the Holy Spirit.

2. Basis: The Spirit applies the death and resurrection of Jesus Christ.

3. Scope: God renews the whole person in his image, including desires, habits, thought, relationships, and actions.

4. Progress: God gives saving graces and strengthens them, so believers more and more die to sin and rise to new life.

The catechism joins God's eternal choice to his work in a person's life over time. Sanctification has a decisive basis in Christ's completed work and an ongoing expression in the believer's growth. See WLC Q. 75–78: Q. 76 concerns repentance, Q. 77 distinguishes sanctification from justification, and Q. 78 explains why sanctification is imperfect in this life. The shorter summary is WSC Q. 35; the confessional treatment is WCF 13.1–3. Compare Romans 6:4–14 and 1 Thessalonians 5:23–24.

Key distinction: Justification concerns God's acceptance of the believer in Christ; sanctification concerns the Spirit's work of renewing the believer.(WLC Q. 77.)

What holiness is for: devotion to God

Build this point from Leviticus 10:1–11, following the deaths of Nadab and Abihu. Verse 10 tells the priests to distinguish holy from common and unclean from clean. These are two distinctions, rather than two ways of saying the same thing.

Unclean / clean: The need for purification and for turning away from what defiles.

Common / holy: Something holy is specially set apart and devoted to God's service.

Main claim: Leaving sin behind is necessary, but the positive goal is to belong to God and enjoy his presence. A clean vessel used in ordinary life and a vessel set apart for worship illustrate the difference. Leviticus also organizes sacred space, priestly access, and sacred times around God's presence; the Day of Atonement is described in Leviticus 16. Christ's sacrifice changes the sacrificial system (Hebrews 10:10–14), while praise remains a Christian sacrifice (Hebrews 13:15).

Interpretive caution: In Leviticus, ritual uncleanness is not always a moral sin. Use the categories to explain the Christian movement away from sin and toward devotion; do not equate every ancient purity rule with personal guilt. (Leviticus 10:10)

From Israel's priests to Christians

Israel is called a kingdom of priests (Exodus 19:6). The lecture treats Israel's priesthood as a picture that points forward; it connects this to Paul's description of the law as a guardian until Christ (Galatians 3:24–25).

Peter calls Christians a royal priesthood (1 Peter 2:5, 9). The professor's point is that every believer is called to priestly devotion through Christ.

Heidelberg Catechism Q. 32, Lord's Day 12 says Christians share in Christ's anointing as prophet, priest, and king. This does not mean every Christian holds an ordained church office.

Christ himself is the source of believers' sanctification (1 Corinthians 1:30). The professor also invokes Irenaeus's picture of Christ's devoted human life as an example; see Against Heresies II.22.4 and the work The Demonstration of the Apostolic Preaching.

Practical takeaway: Ask both “What sin should I turn from?” and “How should this part of my life be devoted to God?” The second question expresses the lecture's positive goal of holiness.

How sanctification proceeds: dying and rising

The lecture uses Jeremiah 1:9–10. God gives Jeremiah words that pluck up, break down, destroy, and overthrow, then build and plant. Jeremiah later repeats the pattern (Jeremiah 18:7–10 and 31:28). The professor applies this pattern to God's work in believers:

Sinful loves, desires, habits, and false ways of thinking are exposed and dismantled. New desires, habits, and conduct are built up in conformity to Christ.

This is tied to union with Christ in Romans 6:1–14: believers share in his death and resurrection, so they are to regard themselves as dead to sin and alive to God. The work reaches the whole person (1 Thessalonians 5:23–24). The professor extends Abraham Kuyper's image of Christ claiming every “square inch” of life to every part of one's own character. Kuyper's phrase comes from his 1880 address Sphere Sovereignty.

Study terms: Mortification = putting sin to death; vivification = being made alive to God.

Two pictures of God's renewing work

Replacement / new creation: A new heart replaces a heart of stone (Ezekiel 36:26–27); the believer is a new creation (2 Corinthians 5:17). The point: Change requires God's powerful, surprising grace. It cannot be explained as ordinary self-improvement.

Renewal / redemption: God circumcises the heart (Deuteronomy 30:6); creation groans for liberation and believers await bodily redemption (Romans 8:19–23). The point: God renews this person and this creation; personal identity and created life matter.

Both pictures matter: God alone gives the grace that makes a new life possible, and the person he renews remains a particular person with real relationships, gifts, and responsibilities. These are complementary images, not a literal account of two separate procedures.

The lecture also discusses the new covenant in Jeremiah 31:31–34, quoted in Hebrews 8:8–12: God's law is written on hearts, his people know him, and he forgives their sin. Reference correction: the “heart of stone” becoming a “heart of flesh” is in Ezekiel 36:26, not Jeremiah 31. Jeremiah's own image is the law written on the heart.

Quick recall

1. Definition: God's gracious renewal of the whole person through the Spirit's application of Christ's death and resurrection. (WLC Q. 75.)

2. Goal: Set apart for God and brought toward his presence. (Leviticus 10:10–11; 1 Peter 2:9.)

3. Pattern: Die to sin; rise to new life. (Romans 6:1–14.)

4. Scope: Every part of a person, over time. (1 Thessalonians 5:23–24; WCF 13.)

5. Tension to remember: God's action is radically new and personally specific. (2 Corinthians 5:17; Romans 8:19–23.)

Questions for review or discussion

1. Why does the professor distinguish clean from holy? What is the positive goal beyond avoiding sin?

2. How do Exodus 19:6 and 1 Peter 2:9 connect?

3. What are the two sides of God's work in Jeremiah 1:10 and Romans 6?

4. What does “new creation” emphasize? What does “redemption” emphasize?

5. Pick one habit, relationship, or responsibility: what might it mean both to turn from sin there and to devote it to God?

Other passages mentioned in passing

Compare the prophetic call stories in Exodus 3 and Isaiah 6 with Jeremiah's call. He also alludes to God's ownership of “the cattle on a thousand hills” (Psalm 50:10). These support illustrations in the lecture rather than its main argument